1. Field of the Invention
The present invention relates to an electronic keyboard musical instrument.
2. Description of the Related Art
An electronic keyboard musical instrument that simulates a grand piano (hereafter referred to as an “electronic grand piano”) generates performance sounds based on waveform data stored therein and does not require strings and other components indispensable for an acoustic grand piano. Therefore, the electronic grand piano can be built with a shorter casing in the depth direction (i.e., the length in a direction away from the keyboard side), compared to a grand piano, whereby space-saving can be achieved, in other words, the space for placing the instrument can be reduced. For the electronic grand piano having such a short dimension in the depth direction, for example, Japanese Patent No. 3928468 and Japanese Laid Open Application 2009-0244713 describe technologies to bring the depth feeling of performance sounds heard by the performer at his or her performing position to be equal to that of a grand piano.
These Japanese patent applications describe technologies in which sounds of a grand piano are sampled at multiple points by a plurality of microphones, and the sounds are reproduced by loudspeakers disposed in the same arrangements as those of the microphones used for sampling. Reproduction of sounds to be generated by one of the loudspeakers located at the back position is delayed, and the sound volume of the sounds is made smaller, compared to sounds to be reproduced by those of the loudspeakers located at the front position, whereby a depth feeling similar to that of a grand piano can be given to the performer.